North Korean leader Kim Jong-Un conducted a large-scale artillery drill targeting the South Korean capital and other targets, hours after the UN Security Council imposed fresh sanctions on Pyongyang, state media said Friday.

The military exercise — targeting five border islands, as well as "reactionary ruling organs" in Seoul and other cities — came as South Korea prepared to unveil unilateral sanctions against the North’s nuclear programme.

"If a war breaks out, such a deadly strike should be inflicted upon the South Korean forces to completely break their will of counteraction at the start and make a clean sweep of them," KCNA quoted Kim as saying.

"Nobody and nothing would survive," he said as he guided Thursday’s drill of frontline artillery units.

The Security Council on Wednesday unanimously imposed its toughest ever sanctions on North Korea, following its fifth nuclear test in September.

The resolution, which was spearheaded by the United States and came after three months of tough negotiations with fellow veto-wielding council member China, caps the North’s annual coal exports — its top external revenue source.

The resolution demands that North Korea "abandon" its nuclear weapons programme, but Pyongyang said the sanctions would only trigger "tougher countermeasures for self-defence".

North Korea has conducted two nuclear tests so far this year. With the fifth test, it claimed major strides in its efforts to fit a miniaturised warhead on a missile that could reach the United States.